List store has 2 items while list is showing 5 items

I am trying to implement an autocomplete field. The results are to be shown in a list. But everytime I make a search the new result is appended to the previous results. I tried clearing out the store attached to the list but it didn't work.
In debugger the store shows 2 items while the list shows many items (2 new + the items from previous search results)